Render or texture paint on cement board cladding?

[philcvk]

Hi - I'm doing an extension in timber frame and on the outside of the studs I have OSB, breathable membrane (roofing felt), battens and cement render carrier boards. 

 

The final look I need is white render to tie into the rest of the house. The quotes to do the render (thin coat or 6mm silicon) are ££££, and so wondered if it'd be cheaper do beading with 200mm of filler around the edges and then prime and paint everything, using a good grade exterior paint? (probably exterior caulk the joints of the cement boards too).

 

I'd be really interested to hear what others have done on render carrier / cement boards for the final layer. 

 

I've heard issues with thin coat render peeling off the cement boards, and nervous about the paint option that this could be one cheap fix not to make. Would be great to know what other people have done, thanks

Edited 10 hours ago by philcvk

[nod]

Unfortunately paint and filler won’t stay on cement board 

Thin coat is fine if it’s done right